Waste streams produced from landfills, livestock, food, and wastewater are sources of methane emissions that could be converted into renewable natural gas (RNG). The supply of RNG from these sources, now and in the future, as an alternative fuel and in greenhouse gas (GHG) mitigation efforts depends on the economic activity drivers of these waste streams and the cost of collecting and converting the biogas to RNG and injecting that RNG into the natural gas distribution system. To inform local energy transition and decarbonization strategies, this study estimates state-level economic supplies for RNG produced from biogas from landfill waste, livestock manure, municipal wastewater, industrial wastewater, and food waste within the U.S. from now until 2050. We estimate both the quantities of RNG available and the prices at which those quantities might be economic to produce from available facility-level data. Thus, we move beyond assessment of technical production potential, which has been the primary focus of estimation to date, to estimating the quantities available and at what prices by state and through 2050. The study’s detailed estimation approach articulates the steps and assumptions associated with estimating future RNG supplies; thereby, facilitating transparency and understanding of results (ours and others), informing analyses and discussion of RNG’s potential decarbonization role, and providing high-level input to RNG technology and project development.
We estimate total waste-based RNG technical production potential to be 398 trillion BTUs in 2025, rising to 478 trillion BTUs in 2050. Over half of that potential is available for under $10/mmBTU, though the vast majority would still require either direct fuel or mitigation incentives to be cost competitive with fossil natural gas. RNG from municipal solid waste stored in landfills is found to be the most economical source of RNG production for most states, though the potential of RNG from livestock manure is also significant. Our study also estimates the distribution of economic supply across U.S. states, with the largest potential RNG supplies associated with the largest projected human populations and dairy and swine livestock operations.
Overall, we find the national aggregate RNG production potential from our waste streams to be modest relative to current natural gas production. However, we find that the economic supply would likely increase with higher effective gas prices, which is exactly what is projected in decarbonization futures. While we find RNG from our set of waste sources to be relatively expensive, we also find clear local opportunities and the potential for waste-based RNG to compete with conventional natural gas and other decarbonization alternatives for higher-cost decarbonization locations and sources.